Motion picture projector



March21943. R J,M ILLER 2,312,663

MOTION PICTURE PROJECTOR Filed Jan. 11, 1939 11 Shets-Sheet 1 a 2 I o /-'/4 BY fia qnypzzif/wllcn M 417012755 11v VENTOR March 2, 1943. J. MILLER 2,31

MCTION PICTURE PROJECTOR Filed Jan. 11, 1939 11 Sheets-Sheet 2 nfill;

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2,1943. R Q ILLER 2,312,663

MOTION PICTURE PROJECTOR Filed Jan. 11, 1933 11 Sheets-Sheet 3 www ' ATTOR 5Y March 2, 1943. R.- J. MILLER 2,312,663,

MOTION PICTURE PROJECTOR Filed Jan. 11, 1959 ll sheets-s heet 4 f W 'H' w 7 H I A; II M v .97 /l /d0 7K. R 6 G @W 5 Z I i 77 155 1a. 5 \q '/0? l l1 E v INVENTOR E- 77 m r my A TTORN s.

March R. J. MILLER 2,312,663

MOTION PICTURE PROJECTOR Filed Jan. 11, 1939 ll sh eetses heet 5 ll h' v "L JEE t I a! W 44/ I INVENTQR $317022! I/Y Z'Z'Zerr M w A TTORNE .5.

March I R. J. MILLER "2,312,663"

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M A TTOR Era.

March 2,1943. R. J. MILLER I I MOTION PICTURE PROJECTOR 11 Shets-Sheet 8 Filed Jan. 11, 3.939-

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March 2,1943. R. J. MILLER 2, MOTION P cTURE PROJECTOR I Filed Jan. 11, 1939 11 Sheets-Sheet 9 INVENTOR yp ma .Z'M'Zlgn A TTORNE Y March 2, 1943; R, J, MILLER 2,312,663

MOTION PICTURE PROJECTOR FiledJan. 11,;1939 ll Sheets-Sheet 1O 11v VENTOR ga /$4,}; J'MZZen ATTOR Ex.

Patented Mar. 2, 1943 UNITED STATES PATENT OFFICE 2,312,663 MOTION PICTURE PROJECTOR Raymond J. Miller, Detroit, Mich, assignor to American Pattern and Manufacturing Co., Detrait, Mich., a copartnership' consisting of said Miller and Alfred E. Wilson Application January 11, 1939; Serial No. 250310 4 Claims.

The present invention relates to improvements in a projector head for a motion picture projector and particularly to improvements in the various assemblies and sub-assemblies of elements which in combination produce a new and useful projector head for projecting intermittently a succession of separate images whereby an illusion of motion is created.

The projector head of the present invention is intended to project the visual images from a continuous strip of film and is designed to be used as one element of a complete projector assembly which includes the film magazine, the sound pro- J'ection head and the illumination source; Since the invention herein disclosed relates to the motion picture projection head per se and not to the other elements of the completed projector, the head alone is shown and described in the present application, it being understood by those skilled in the art that the head embodying the present invention may be used in combination with the other elements required for the complete projection of visual images synchronized with sound.

It is among the objects of the present invention to provide a motion picture projector head of simplified design and construction, which is adapted for economical production, service and operation and in which the various component assemblies and sub-assemblies of elements are of improved design and construction and are combined to produce a motion picture projector head having improved operating qualities.

Other objects and advantages of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views, and in which 7 Fig. 1 is a View in perspective of a projector head embodying the present invention and showing the front and non-operating side of the-projector head.

Fig. 2 is a rear elevation of the projector head shown in Fig. 1.

Fig. 3 is an enlarged side elevation of a projector head embodying the present invention with parts broken away and. showing the operat-' ing door in the open position to reveal the interior arrangement of the projector head shown in Fig. 1.

Fig. 4 is a stagger'edjsection taken substantially on" the line 4 4 of Fig. 3 in the direction or the arrows.

Fig. 5 is a section taken substantially on the line 55 of Fig. 4 in the direction of the arrows and showing a cross section through the entire projector head substantially at the center axis of the horizontal operating shaft.

Fig. 6 is a section taken substantially on the line 6-6 of Fig. 5 in the direction of the arrows and showing a cross section through the oil filler and filter capsule.

Fig. 7 is a section taken substantially onthe line I -1 of Fig. 5 in the direction of the arrows and showing a cross section through the back cover and main housing showing the end of the. compensation slide housing.

Fig. 8 is' a section taken substantially on the section line 8-8 ofFig. 3 in the direction of the arrows and showing a top plan view of the magazine adapter with the fire valve roller carrier tray in position, the dotted line View showing the tray in its removed position. I

Fig. 9 is a cross section taken substantially on the line 9-9 of Fig. 8 in the direction of the arrows. 7

Figs. 10', 11 and 12 are each sectional views taken substantially on the respective lines I0-l 0', HI| and l2-l2 of Fig. 8, each view being taken in the direction of the arrows.

Fig. 13is a fragmentary sectional view taken substantially on the staggered section line |3l3 of Fig. 4 in the direction of the arrows and showing the focusing mechanism and adjustment.

Fig. 14 is an enlarged section of the portion of the projector head shown in the circle I4-.-l4 of Fig. 13 and showing the action of the locking camon actuation of the aperture carrier.

Fig. 15 is a fragmentary section taken substantially on the line I5|5 of Fig. 5, which passes through the projector substantially at the center line of the upper feed'sprock'et.

Fig. 16 is a fragmentary section taken substantially on the staggered line Iii-I6. of Fig. 5 in the direction of the arrows and showing the hydrau- In; control cylinder of the fire shutter and a cross section through the intermittence movement.

the drive shaft and the intermittence movement flywheel.

Fig. is a section taken substantially on the line 20-20 of Fig. 16 in the direction of the arrows and showing the intermittence housin from the front view with a cross section through the eccentric adjustment ring.

Fig. 21 is across section taken substantially on the line 2l.2l of Fig. 16 and showing the relationship of the star and cam of the Geneva movement. I

Fig. 22 is a fragmentary section taken substantially on the line 22--22 of Fig. 3 in the direction of the arrows and showing a cross section taken through the fire trap of the aperture plate substantially at the point of the guide rollers. This View is taken from the front of the machine with the fire shutter in the closed position. 2. N

Fig. 23 is a view similar to Fig. 22 but showin the fire shutter in the open position.

Fig; 24 is a section taken on the staggered sectionline 24-24 of Fig. 16 in the direction of thetarrows and showing the relationshipof the segment ring to the intermittence movement.

Fig; 25 is a fragmentary section taken substantially on the staggered line 25-45 of Fig. 22 in the' direction of the arrows and showing a cross shutter blades and the counterbalance and backing plates of each shutter blade.

Fig. 37 is a fragmentary section taken substantially on the staggered section line 31-41 of Fig. 35 in the direction of the arrows and showing a cross section through the split locking arm on the framing shaft.

' Fig. 38 is a fragmentary section taken substantially on the staggered section line 38-38 of Fig. 4 and showing a cross section through the oil pump and check valve.

Before explaining in detail the present invention it is to be understood that the invention is not limited in its application to the details of construction andarrangement of parts illustrated inthe accompanying drawings, since the invensection of the projector head taken substantially through the center axis of the lens carrier. I

Fig. 26 is a fragmentary section taken substantially on the line 2526 of Fig. 25 and showinga cross section taken substantially through the aperture pressure plate housing at approximately the center line of the attachment cone.

Fig. 27 is a view in perspective of the adjustable spring plate and the alignment aperture pressure plate; A

Fig. 28 is a fragmentary section taken substantially on'the line 28-28 of Fig. 3 in the direction of the arrows and showing a cross section through the lens carrier and the lens withdrawal tube.

Fig. 29 is a'sectional view taken substantially on the line 23-Z9 of Fig. 28 in the direction of the'arrows and showing a the lens carrier.

Fig. 30 is'a fragmentary section taken substantially on the line'303fl of Fig. 29 in the direction of the arrows and showing a cross section through the lens carrier.

Fig. 31 is a view in perspective showing the withdrawal ring forming a part of the lens carrier assembly and showing the indexing slots and locating taper construction. 7

Fig. 32 is a fragmentary section taken substantiall on the staggered line 32-32 of Fig. 5 and showing a cross section taken substantially throughthe shutter.

Fig. 33 is a fragmentary section taken substantially on the line 33-33 of Fig. 32 in the direction of the arrows and showing a cross section through the shutter and housing looking toward the impeller plate.

Fig. 34 is a-section similar to Fig. 32 but show ing a modified form of the light shutter mechanism embodying the present. invention.

Fig. 35 is a fragmentary section taken sub' stantially on the staggered section line 35-45 of cross section through tion is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

A motion picture projector head embodying th present invention comprises a plurality of separate but interconnected assemblies and sub'- assemblies of mechanical movements, each of which performs its intended function at a given time in the entire combination comprising the projector head of the present invention.

The description of the projector head shown in the accompanying drawings willproceed by reference insofar as possible to the component assemblies and sub-assemblies of elements which are designated generally in the several views by letters as follows:

A.-Magazine adapter containing fire valve nism therefor.

is placed on the magazine adapter 5' which has a General description of parts Referring to Figs. 1 and2, the external parts of the motion picture projector head embodying the present invention comprise a casing I having a removable side p late 2 constituting the nonoperating side of-the head and a hinged access door 3 on the opposite or operating side of the head. The film magazine 4 shown in dotted line removable clean-out tray 6 containing the rollers for the fire valve (to be hereinafter described):

The upper film magazine (not shown) is mount ed on the mounting 1' provided. therefor on the *top of the housing I. v 'The lens tube 8 is shown in the retracted position in the solid line and in. 'the withdrawal position in the dotted line. The

lens controlknob 9 for actuating'the lens carrier and=focusing the lenses is placed beneathgthe.

lens tube 8 and is maintained in adjusted position by the lens control knob locking ring). The fire trap control knob l I extends through the outer face of the casing I at a point adjacent the lens control knob 9. An oil drain plug I2 may be removed from the face of the casing to provide drainage of the oil from the oil sump contained therein. The main drive shaft I3 extends through the housing I and is connected with the sound head (not shown) for transmitting driving power to the interior mechanism of the projector head of the present invention. The

shaft I3 is surrounded by an oil seal l4 which prevents leakage of the oil from the interior of the casing I.

A plurality of framing control knobs I5. placed one on each side of the housing permits control of the framing of the images in the projection head. Oil is introduced to the inside of the casing I through the oil filler cap I6 having a filter for filtering the oil supplied to the interior of the casing. The rear aperture plate I! (Fig. 2) is secured to the main housing I. The electrical inlet I8 for the framing light is also shown in Fig. 2. The shutter housing I9 and one of the shutter blades 20 are also shown in Fig. 2. A handle 2I is provided for opening and closing the access door 3.

Referring to Fig. 3, the details of the interior mechanism of the projection head of the present invention are there shown. As there shown, an observation port 22 is provided in the shutter housing in order to permit the operator to determine the position of the shutter in the hous-- ing prior to threading the machine. A focusing spot 23 covered with semi-opaque glass is provided for observing the focusing of the projection light on the aperture plate. The rear aperture plate I! is provided with a convex clearance 24 to permit the passage of the film therethrough after it leaves the intermittence drive sprocket. The oil level in the sump is shown through the oil level observation glass 25.

The removable lens adapter 26 is provided on the outside of the machine and cooperates with the other portions of the lens carrier as will be hereinafter described. The fire trap 21 is integral with the rear aperture plate and contains the fire shutter, the framing light and the switch. The movable aperture pressure plate housing 28 contains the movable aperture plate which retains the relative position of the film shoes and the spring tension plate and adjustment cams for the same, as will be hereinaftermore fully described.

An electrical switch, indicated generally by the numeral 29, is provided for operating the hereinafter more fully described. A control knob 32 is provided forcontrolling the lock and permitting the removal of the movable aperture pressure plate housing. Tension on the film shoe springs (not shown) is provided by the control knobs 33.

A plurality of guide bars 34 are secured to a bracket 35 and are mounted on the housing I.

and provide support for the lens carrier and the movable aperture pressure plate housing in response to movement of the focusing knob 9.

An operating lever 36 is provided for moving and locking the movable aperture pressure plate housing. The lens carrier focusing screw, indicated generally at 31, contacts with the lens carrying bracket and causes its movement in response to movement of the focusing knob 9. The intermittence movement is contained in a housing 38.

An oil seal cap, indicated generally at 39, is provided on the end of the double bearing arm of the intermittence sprocket (not shown in this view). A film tension shoe 40 is provided on the intermittence sprocket and acts to hold the film at a given tension in contact with said intermittence sprocket. A door catch 4| is provided for holding the access door 3 in the locked position.

Film is fed through the projection head of the present invention through upper and lower feeding sprockets and guide rollers which comprise the feed sprockets 42 and 43. the sprocket guide rollers 44, 45 and 45a associated respectively with the feed sprockets 42 and 43 and carried respectively by the arms and actuating levers 46 and 41. The guide rollers 44, 45 and 45a are adjustably mounted on eccentric shafts, as hereinafter described, and are maintained in adjustment by the adjustment locking screws 86 and 81. The opening and closing contact of the guide rollers 44, 45 and 45a with the sprockets 42 and 43 is controlled by the guide roller operating handles 88 and 89.

Retaining caps 48 and 49 are provided on the arms 46 and 47, respectively, and are provided with springs (not here shown but hereinafter shown and described) for applying tension through said arms to the guide rollers 44 and 45. Stripper plates 51! and 5I are associated with the sprockets 42 and 43 and prevent jamming of the sprockets in the event of film breakage and are adjusted by adjusting screws 84 and (Fig. 4). In threading the machine, the guide rollers 44, 45 and 45a are moved away from the sprockets 42 and 43 and provide a clearance to permit the sprocket holes on the film to be readily placed in alignment over the drivin extensions on the sprockets 42 and 43.

Lubrication of the guide rollers is accomplished from inside of each guide roller through oil holes 52 and 53 which are closed with a resiliently held ball seal., The upper guide rollers in the fire trap, as will .be hereinafter more fully described, are similarly lubricated through resiliently held ball seals 53.

Movement of the aperture plate housing 28 to permit threading of the machine is permitted by movement of the telescoping ring 54 of the lens assembly which is adjacent the lens carrier 55 which contains a taper 56 and a bayonet attachment 5! which permits removing the lens adapter 26 as a unit from the lens tube (see Figs. 28 to 31) A rubber sealing ring 58 is provided around the lens adapter and serves to prevent air from being drawn into the projector head around the lens holder. The gear train carrier, tobe hereinafter more fully described, is removable as a unit from the projector head by removal of the gear train removing screws 53 and 60. The intermittence mechanism is removable as a unit from the housing by removal of the intermittence housing retaining screws 6|.

Other parts of the projector head of the present invention, as will be more fully described hereinafter in connection with the respective sections to which they are.related,.comprise the lens bracket 35which is secured. to. the .mainhousing bya plurality of screws 90, whichlcarrieslthe plurality of guide. bars 34 .which. are. secured .to the bracket 35 by a plurality of, screws 9L ,The aperture pressure plate housing. 28;is .movedpby. the actuating cam androller 92 which is oper-f ated by the actuating lever 36. The actuating shaft connected with thelever i3 .is journalled in a bearing 93 on the bracket and is controlled by a collar 94 which controls the arc of ,mdvement of theactuating lever and cam... L. I

Oil is supplied to the interior of vthel'iousing and is maintained in the oil sump 95 which is separated from the remainderof the housing by. the interior wall 96. ,The oil is drawnfrom thesump by the pump I6 and distributed to the various parts of the mechanism. As shown in Fig. 5, the oil filler cap I6 is provided with a filter member 91 which filters all oil flowing into. the sump.

The assembly of these parts is shown in Fig. 6 and as there shown, they comprise the wall 98 .of the capsule which is secured to the casing I', and the filter member 91 which is secured ,to'the wall 93 by the stud 99. The oil line I! sup-' plies oil from the pump I6 to the intermittence movement, and an oil line I02supplies oil from the pump I6. to the shutter drive mechanism.

As shown in Fig. 5, the vertical shaft. 63; is journalled as at I00 on suitable bearings, such for, example as ballbearings. The intermittence. movement is driven from the shaft 65 by gears. I03 and I04. The shutter D is driven from the shaft I05, havinga drive gear I meshing with thespline gear I01 which is carried on and driven by the horizontal shaft 65. The horizontal shaft 65 is journalled in bearings I08 and I09. The shaft 65a connected with and driven by the shaft 65 is mounted on bearings III) and I II located on the ends thereof. The bearings H0 and III. provide. an anti-friction mounting for the spline gear I0! and are adjusted by theadjustment nutl II2 on the bearing H0 which is locked in the adjusted position by the spring locking ring H3. The horizontal shaft 65 is definitely located by a. shoulder I I4 which is cast integrally in the hous-I ing and which acts as an aligning stop for. the bearing I08.

The compensation slide housingIIB is actuated by movement of the framing shaft ill which is actuated by theframing control knobs. I5 connected therewith. The shaft II! is connected with the compensator slide member by the; beveled gear I I8 and a lead screw II9 journalled in the bearing I and having a nut I2! engaging the threads of the lead screw. The nut I2I is operatively connected with an arm I22 which issecured to the compensator slide housing MB This construction is shown in detail in Fig. '7.

As shown in Fig. '7, the end of the shaft 65a is journalled in ball bearings III which are seated on a shoulder I24 formed in the compensat ing slide housing H6 and which in cooperation with the bearings H0 and III keep the spline gear I01 in position; i

Bosses I25 and I25 are provided to receive the screw-threaded connections with thesound; head (not shown). The fire trapcontrol valve knob II is connected with the shaft I2 1 which connects the knob II with the check valve (Fig;

Gear train and gear train carrier 1 shown in Fig. 4, the driving gears andldrive shaftsof the projectorhead embodying themes-.1.

ent invention are carried onageartrain carrier 62 which gca'rries andisupports a11..of thergears, shafts and" bearings of the entire drive mechanism and thus insures-a predeterminedand fixed accurate alignment of the parts. The entire "gear train carrier. isremovable. asa unit from the. projector head by removal of thescrews 59 and 60. The gear train and shafts carried .by. the carrier 62 comprise the vertical shaft 63 which is driven from the main drive shaft I3 by a setof main drive gears 64 which are driven by the shaft .I3 and which transmit a driving force. to the shaft 53. The vetrical shaft 63 drives the horizontal shaft 65 through. gears 66 and. 61. The horizontal shaft 65 drives the intermittence movement and shutter and has a splined section 55a (Fig.5). I i

The upper and lower drive sprockets 42 and 43 are driven by upper and lower sprocket drive shafts 68 and B9which in turn are driven from the vertical shaft 63 by gearslfl connecting the shaft 63 and the shaft 68, and gears I.I- oonnecting the shaft 63 and the shaft 69. The end of the-shaft 68 is journall ed inball bearings I2 and the ends of the shaft 69-are journalled in ball bearings 13. The mainshaft I3 is journalled inballbearings "and I5. w v 1 I The gear train carrier 52 is located in the housing by holes in bosses and BI which register with dowel pins 82 and 83 in the casing.

I Lubrication of operating parts -'The.various operating. mechanisms are 1ubricated and the fire shutter is operated hydraulically by oil which is circulated under pressure by the oil pump I6 which pumps oil from the sump 95. through theoil feed line H which leads "to the fire shutter operating cylinder. Oil is also supplied to the oil line I8 which supplies oil to the .top of the gear train. The flow of oil through the line I1 is controlled by the check valve. I9 which can be adjusted to create predetermined pressures in the hydraulic cylinder for operating thefire shutter (see Fig. 38). 1

Magazine adapter, fire rollers and clean-out K tray .In Fig. 8 is shown the magazine adapter 5 with the. removable tray '6 shown in the closed'position' in. the solid lineview and in the removed.

position in the dotted line view. As here shown,

the tray 6 slides on the guide rods I28 and containsjthef largefire valve roller I29" and a;plu;-

rality of smallerrollers I30, the top one of whichonly is shown in this view. The. tray'fi'isheld in;

the tray. The magazine adapter 5 is removably slgtgured to the casing I by a plurality of screws Further details of construction of the magazine adapter 5 are shown in Figs. 9 to 12, inclusive. As there shown, the rollers I29 and I30 revolve each ona separate, shaft I34. As shown inFig. 9, the film passes from the magazine adapter 5 to the interior of the casingand through theupper feed sprocket through the film slot 35. As shown in Figs. 11 and 12, the rollers I29 and I30 revolve freely each about a separate shaft I34. The outer surfaces of the rollers I30 are spaced slightly from each other and spaced slightly from thesurfaceof the roller I29.

Each .of the shafts I34. .held. inplaceby ha screw-threaded members I35 at one end and female screw-threaded members I31 at the other end, each of which is provided with an oil duct I38 communicating with an oil duct I39 in each shaft I34. The rollers I29 and I30 are spaced on the shafts I34 by spacing collars I40. The fire tray 6 during operation of the projector is contained in the magazine adapter 5. During the process of running the film, the film dust, chips, etc. are collected in the tray 5. In conventional construction the tray is not removable and is cleaned only with great difliculty. The accumulated particles in the fire trap are frequently the cause of film fires in the projector head.

In the projectorhead of the present invention, the fire rollers I29 and I30 contained in the orig-- inal frame 6 slide into the magazine adapter on the guide rods I28 and thus permit a ready removal of the fire trap and a cleaning of the .fire trap outside of the projector head.

In the normal position the tray is held in the magazine adapter by the spring-pressed balls I3I which engage the grooves I3Ia on the guide rods and hold the tray against accidental removal. The tray for cleaning purposes is caused to slide forward on the guide rods. It will be seen that in so doing it is not necessary to disturb any other parts of the projector or to remove the upper magazine.

The oiling system for the rollers in the valve, as previously described,oils the rollers from the inside of the shaft so that oil must pass the entire length of the rollers before it can be thrown off. At this point the rollers extend beyond both edges of the film so that the oil does not contact the film surface. The oiling is accomplished by the provision of the oil inlet hole I38 which passes through the female screw plugs I31 and are aligned with the oilhole I39 in the center of each shaft I34. On the other end of the shaft is a recess in which fit the male screw plugs I35. The combination of the male plugs and the female plugs holds the shaft rigid so that the roller alone revolves. The male and female plugs hold the shaft and also permit lateral adjustment thereof, which in turn controls the lateral adjustment of the rollers.

On each male plug is placed a small collar I40 which rides freely on the plug between the frame andthe roller and serves to keep the roller in a predetermined position.

Aperture pressure plate carrier and lens focusing adjustment The aperture pressure plate and lens focusing carrier are shown in enlarged views in Figs. 13 and 14. As there shown, the bracket 35 carries a plurality o-f parallel rods 34 which act as guide bars for guiding movement of the lens carrier and the movable aperture pressure plate housing and secured to the housing I by a plurality of screws 99. The plurality of parallel rods 34 are secured tothe bracket 35by a plurality of screws 9I. The aperture pressure plate is carried on the aperture pressure plate carrier II, which has bearing surfaces I42 engaging the topmost rod 34, and bearing surfaces I43 which engage the middle rod 34. Thus the aperture pressure plate carrier is supported in two planes in a rigid manner and is permitted to move in a plane parallel to the axis of the rods 34 and is guided in such movement by the bearing surfaces maintained in contact with the surfaces of the rods The lens carrier 55 is provided with bearings I44 contacting the middle rod 34 and a plurality of bearings I45 which contact the lower rod 34. By this construction the lens carrier is supported in two planes by the rods 34 and is permitted to move in a plane parallel to the axis of said rods.

The focusing of the lens is accomplished by movement of the lens carrier 55 in a plane parallel to the rods 34. This is achieved by movement of the lens-focusing knob 9 which is connected with the lens-adjusting screw 31 which is connected with an adjusting nut I 41 which in turn is carried by the carrier 55 and is movable on the screw 31. To secure accurate adjustment and eliminate backlash between the threads on the screw 31 and the nut I41, there is provided a spring I48 which applies tension to the focusing nut I41 causing its threads to contact with but one side of the threads on the adjusting screw 31, thus giving in effect a micrometer adjustment. The screw 31 is journalled in a hearing I49 secured in the main casing I which also acts as a retainer for the locking ring I0 which bears on the split ring I50 to hold the adjustment of the screw 31.

In focusing the lens, the focusing knob 9 is turned, which causes the focusing screw 31 to revolve. After the desired focus is obtained, the lens-focusing locking nut I0 is turned. On the inside of the nut I0 and the retainer is a female taper which engages with the male taper on the split ring I50. Thus, as the nut I0 is turned inwardly, the surfaces come together, causing the ring I50 to constrict about the screw 31, thus locking the screw 31 in the desired position. In

this manner, the focus of the lens can be locked and because of the lens holder embodying the present invention, the lenses may be removed and replaced without disturbing their focal plane in relation tothe carrier.

The movement of the aperture plate bracket I 4|. is accomplished by movement of the actuating cam 92, which opens, closes and locks the aperture pressure plate carrier, depending on its position relative thereto. The cam 92 is moved by movement of the actuating shaft I5I which is op'eratively connected with the actuating lever 30. The cam arm 92 carries a pin I52 which carries aroller I53 (Fig. 4), which moves in an actuating. slot I54 provided in the aperture pressure plate carrier MI. The aperture pressure platecarrieris maintained in adjusted position against the tension of a spring I 55.

The operation of the aperture pressure plate carrier is as follows: When the actuation lever 35 is turned in a clockwise direction, it causes the cam arm 92. to revolve likewise. The roller I53 on the pin I52 of the cam arm 92 moves upwardly in the slot I54 of the aperture pressure plate carrier MI and. causes it to move forward,

- thus openingthe aperture pressure plate to give access for threading film into the machine. When the film is placed in the machine, the actuating lever 39 is rotated in a counterclockwise direction, causing the roller I 53 to move downwardly through the slot 154, closing the aperture pressure plate. As the roller I 53 passes dead center in the slot I54 and is moved to a predetermined position as permitted by the locking collar 94 on the actuating shaft (see Fig. 4), the aperture pressure plate is locked in the closed position. The stop on the bushing 93 controls the amount of actuation of the aperture pressure plate, as above described. The spring I applies pressure on the actuating arm and the slot and this is transmitted through the roller to the stop onthe collar. 7 Thus, the aperture pressure plate cannot be forced open by a patch or other ob,- struction on the film as it passes through the machine, sincethe pin I52 and the roller I53 are maintained at a point below dead center of the slotI54, l p

The foregoing described construction is shown in larger scale in Fig. 14, in which the dotted line view shows theparts in position when the aperture carrier plate is open. .The solid lines show the parts in the lockedv position. The stop 94a bearing on the slot 93a is here clearly shown. Adjustment ofv the aperture pressure plate is maintained by an adjustable locking device which is shown in this'view and which is also shown in Fig. 26. The arrangement of the parts is such as to permit ready removal of the aperture pressure plate as a unit from the projector head.

As shown in these views, the aperture pressure plate is secured to the carrier MI by a male cone I56 carried by a portion of the housing- The aperture pressure plate is located relative to the carrier MI by a locating pin I51 which is carried on the plate I58. The plate I58 isadjustable in order to adjust the position of the cone I56 and the pin I51 relative to the carrier MI. The aperture pressure plate is removably locked on the cone I56 through a locking slot I59. 4

Referring to Fig. 2 it will be seen that the aperture pressure plate housing I66 is provided witha female cone member I6I, which mates with the male cone I56 and with a boss I62 havingan opening I63 which is adapted to register with the pin I51. The housing I66 is locked and. unlocked in. position on the cone I56 by a lockingkey I64 which extends inside the cone I56 and through the slot I59 and engages the inside surface of the cone I56.

The locking key. I 6 is. moved by the locking shaft I65, which'in turnis moved by the actuating knob. I66 and is maintained in locking position by tension of the spring I61.

.Frequent removal of the aperture pressure plate housing. I66 is desirable in order to permit cleaning of the pressure plate and housing and. in order to permit cleaning of the film tracks. Theremoval of the aperture pressure plate and the housing as a unit is accomplished by turning the lock. I64 from the vertical position to a horizontal position so that it is aligned with the hole I59. In'this position the lock I64 can be withdrawn and the entire housing I69 may then be removed from the tapered cone I56.

In replacing'the aperture) pressure plate, the guide pin I51, whichis fastened on the adjustmritjplate I58, enter'sa. hole I63 in the boss I62, "I which I gives primary alignment. The. com -v plte'; alignment; is byfcontact of the parallel planefsurfaces of the border of the aperture housing I66 'coming'in contact withthe face (if the fir trap 21. This achieves the alignment of the entire housing in a'vertical plane. The housing l I66 .is pressed firmly back. until the femaleconeltl contacts themale cone 156.. The knob "I66 whichactuatesthe lock is then pressed inwardly towardthe conesandagainst the tensionof thespringlIBT until the lock I64 occupies a positioninside the male cone I56. The knob is then rotated 90 and the lock fitsinto shallow grooves I59a (Fig. 13). After passing through the'grooves I 59a,.the knob I66 is released'and the lock engages the inner surface of the male cone I56, thus-holding the parts securely in the assembled position. .i l

- Aperture plate and film shoe adjustment mechanism The details of the aperture plate and film shoe construction are indicated generally by the letter H and are shown particularly in Figs. 25, 26 and 27. As hereshown, the aperture plate 214 is secured to the fire trap housing I66 by a plurality of screws 214a and is provided witha masking plate 215 and an alignment pressure aperture plate 216. These parts are all carried by the movable aperture plate housing 28 which is removably held in' place in the fire trap I66 by a plurality of removable screws 214a.- The alignment pressure aperture plate 216" carries a plurality of shoes 219 which ride on the film to hold itagainst the film track. Spring pressure is applied to the shoes 219 by a plurality oiduplex springs 286 which are carried by an adjustable spring plate *28I whichis removably secured in place by a plurality-of screws 282.

' The adjustable spring plate 28I is aligned with and secured to the aligned pressure aperture plate 216 by a plurality of aligning screws 283. Tension on the springs 286 is controlled by aplurality ofadjustable tension cams- 264 which bear each on an equalizing vane 285 car apertures which-are'aligned to form thealign'ed aperture 281 which registers with the open'apex' of the light cone 268 which leads to the aperture plate-214 through the fire trap housing I66.

The open end of the cone 288 is closed by the fire shutter 233, as previously described, when the machine is not in operation. As shown in this view, the fire shutter is preferably constructed of spaced plates 289 and 296.

Ventilation of aperture plate and adjustment of spring shoe tension on the film The flow of ventilating air currents through the aperture plate 214 is directed by a plurality.

adjustment knobs 284a extending outside of the operating sideof theaperture housing I66. The

adjustment of. the cams by the knob is held in placebythe serrated collars 286a, eachof which is in contact with the V-lip of a tension spring 286 which engages the serrations in the collars 286a. This retains the adjustable position of the cam 264 after the desiredtension has been set. The adjustment cams ride on vertical vanes 285 mounted on the adjustable spring plate 28I. This allows the adjustable spring plate 28I to rock upon the guide screws for equalizingspring tension on each side of the film. With this arrangement of the spaced cams 284, the operator may apply different tension at the top and bottom of the pressure shoes 219. In this manner it has been found that a desirable operation results from the use of lower pressures on the top film shoes with a steady increase in the pressure toward the higherpressures which are applied to the bottom spring shoes. In this way the film is guided with less side sway than where the tension 0 all of the spring shoes is equal.

The foregoing construction and assembly of the aperture pressure plate is shown more clearly in Fig. 27, where the parts are shown in an assembled position and may be removed as a unit from the housing I 6|]. As will be seen, the members are removable and replaceable as an assembled unit from the housing I60, which is a desirable feature permitting a ready cleaning of the aperture and the aperture plates.

In Fig. 27 is also shown clearly the construction of the film tension shoe which guides the film to the intermittence sprocket 209. As shown in Fig. 2'7 in perspective, and as shown in section in Fig. 26, the film tension shoe 40 comprises a sprocket shoe 292, which is so formed as to permit clearance of the film and the sprocket teeth. A tension spring 293 is mounted on a screw 294 secured to the alignment aperture pressure plate and is spaced therefrom by the spacing collar 295. The spring 293 exerts a tension on the sprocket shoe 292, which keeps the film at a desired tension and in contact with the teeth of the inter mittence sprocket 209. As here shown also, the intermittence sprocket is provided with the stripper plate 209a to prevent jamming of the sprocket in the event of breakage ofthe film.

Adjustment of aperture plate to eliminate keystoning projected through the aperture plate may be shown on the screen in such a way that the image as shown on the screen is in focus on all parts of the screen. This eliminates a defect present 3 in conventional types of projection apparatus which is commonly referred to as keystoning, as a result of which parts of the projected image appear on the screen in a distorted and unfocused condition. By adjusting the aperture plate as above described so that it lies in a plane substantially parallel to the plane of the screen, I have found that the defect of keystoning is substantially eliminated in the images projected through the projector head embodying the present invention.

. Filmfeeding sprockets and guide roller assembly in the lower assembly except that two guide roll-l ers 4'5 and a are used with the sprocket wheel instead of the single guide roller to be hereinafter described.

j The details here to be described are found in Figs. 15, 17 and 18, which show, respectivelyfa fragmentary cross section through the projector head substantially at the center line of the upper" feed sprocket, and details of the sprocket and guide roller assemblies. As here shown, the sprocket 42 is secured to a stub shaft I68, which is connected in driving relation with the sprocket drive shaft 58. An oil seal IE9 is provided around the shaft I68 to prevent leakage of oil from the interior of the machine. The drive shaft 68 is journalled on its ends in ball bearings I10 and Ill and is driven from the vertical shaft 63 through the drive gears I0. The stripper plate 50 (Fig. 4) is supported on the stripper plate bracket H2. The guide roller 44 is mounted for rotation on an adjustable eccentrically mounted shaft I13, which has an eccentric connection with the carrier arm 46. The arm 46 rests in the closed position on the boss surrounding the sprocket shaft.

To obtain clearance and adjustment between the guide roller 44 and the sprocket 42, the guide roller shaft I13 is provided with a screwdriver slot on the outer end (not shown), by mean of which the shafts may be rotated to secure the desired adjustment of the rollers. .The eccentric connection with the bracket at the other end of the shaft increases or decreases the distance between the roller 44 and the sprocket 42. After the desired adjustment has been obtained, the set screw 86 secures the shaft I I3 and the roller 44 in the adjusted positions. It will be seen that the adjustability of the guide rollers is particularly important in the lower sprocket assembly as the two guide rollers 45 and 45:: must be aligned in relation to the sprocket 43.

In the machines of the prior art the guide rollers 45 and 45a cannot be adjusted independently of each other since it is conventional practice to secure the rollers directly to the arm and to permit only an adjustment of the entire arm without the separate adjustment of the separate rollers.

The guide roller 44 is lubricated from inside the shaft I13 by an oil duct I" which communicates with a spring-pressed ball sealing member 52. From the ball valve oil sealing member 52, an oil hole I I4 extends through the axis of the guide roller shaft I'I3 to a point midway between the extremities of the rollers. From there it leads to the surface of the shaft. Thus, when oil is applied, the bearing is oiled the entire length of the roller and any excess oil which escapes at the end of the bearing is caught by the extending rim I15 of each roller and is thrown off the roller by centrifugal force due to its rotation outside the path of the film. Thus, no oil gets on the surface of the film. I

Each guide roller is maintained on the shaft by a split ring I16 which rests in a groove on the end of each shaft I13. The lever 88 and the bracket 46 are pivotally mounted on the stud I1! and are maintained in position by a spring I18.

In threading up the machine, it is necessary to raise the guide rollers 44 off the sprocket 42. After the film is pressed on the sprocket 42, the roller 44 is closed down to hold the film in contact with the sprocket. The roller 44 must be held under tension so that the film cannot lift it out of position. This tension is provided by the fiat spring I'I8 secured to the arm in the recess as shown in Fig. 18. The end of the spring I78 rides on a round shaft-like cam I19 having a fiat spot I80 which gives purchase to the spring when the roller 44 is closed on the sprocket 42. Tension is adjustable by varying the position of the flat spot I80 in relation to the sprocket 42. After adjust ment has been made, the cam I19 is locked securely to the main casing by means of the screw stud II'I.

The arm has a bearing IBI on each end of the journal which rides on the round portion of the cam I79. The removal of the arm from the machine is eifected by removal of the cap and discharges oil into the oil inlet I91.

r'otatingthe spring I18 off 'the flat spot I8I and drawing the same forwardwithout disturbing the setting of the cam I19. The cap 88 screws on to the head of the cam stud I11. The actuating lever 88 by which the guide roller 84 is opened and closed, is such that no strain is placed on the rollershaft when the roller is raised and lowered. This keeps the roller in the desired alignment with the sprocket during the life of the machine. 'As shown, the spring I18 is secured to the arm casting I48 by a screw E82 which may be inserted and removed through the hole I83.

Interntittence movement The intermittence movement is indicated generally by the letter E in the several views and is shown in detail in Figs. 16, 19, 20 and 24, to which referencejwill now be made.

- "As shown in these views, the i'ntermittence' movement is mounted as a unit in the intermittence movement casing 88 and may be removed as a unit and without disturbing its synchronized adjustment with the other parts of the device, by removal of the casing 38 from. the machine. The intermittence movement comprises the intermittent blrive shaft I84 which is journalled in ball bearings I85 and I88 on opposite ends of the shaft and is spaced by collars I81 and I88. The shaft I84 is connected with a flywheel shaft I89 by a splined connection I98. The flywheel I9I is connected with the shaft I89 and is driven thereby and in turn drives a gear I92 which meshes with the gear I93 and the cam shaft I98. The flywheel shaft I89 is journalled in a bushing I95 and the cam shaft I94 is journalled in a bushing I88.

Oil is admitted to the intermittence movement fromthe'pump 18 by the oil supply tube IOI which through the intermittence movement and out of the intermittence movement housing through the oil outlet I98. The casing 38 comprises a front wall I99 and a back wall 288. The intermittence movement is held'in place by the threaded ring 20I (Fig. 24), which holds the intermittence retaining ring 282 in connection with the main casing and in adjustment relative thereto.

The adjusting ring 28I is held in an adjusted position by means of a spring washer 28 id which acts substantially as a pressure washer in the assembly. This is shown in section in Fig. 16.

Leakage of oil from the intermittence movement to the case of the machine is prevented by the oil seal ring 282a, which is placed between the member 282 and the adjacent flange of the main casing.

Around the periphery of the ring 282 is provided a segment of spur teeth 283 (Fig. 24) which engages with the framing gear. An eccentric adjustment ring 284 is provided to assist in the adjustment of the intermittence movement, as will be hereinafter described.

The Geneva movement forming a part of the intermittence movement consists of a pin and cam 285 and a star gear 288 (Fig. 21), which is mounted on a star shaft 281 which is journalled in the bushing 288 and drives the intermittence sprocket 289 which is locked by thepins 2I8 onto the shaft 281. The end play adjustment of the shaft 281 is provided by laminated shims 2 II. Lubrication of the bearings is accomplished through the ball oil seal 2I2. The entire intermittenee movement and the housing is maintained in place by a plurality of removable screws 2 l 8. The segment ring 28I is provided with a slot which is constricted by the screw 2M. 1

When it is necessary to removethe intermittence movement from themachine, the screws 2I3 located symmetrically about the retaining ring 282 are loosened. The intermittence movement is then rotated counterclockwise so that the ends of the retaining screw come into position over the clearance slots 2I5 (Fig. 20).

The entire intermittence movement may then be pulled from the case without disturbing any of the gears or'other moving parts thereof. The disengagement is permitted by means of the spline connection I98 on the rear of the flywheel- I9I. In replacing this movement or in substituting another movement for the particular intermittence movement in the machine, the spline connection I98 on the flywheel I9I is so designed that it can only engage the spline on the intermittent drive shaft on the gear train carrier in one position through 360 of movement. The movement of the intermittent sprocket 289 is thus synchronized with the shutter of the machine, whereas in prior projector heads, when the intermittence movement is removed as is frequently required for service and cleaning operations, it is necessary to move the gears out of mesh and when replacing the movement to resynchronize the movement and the shutter. This operation is eliminated by the use of the mechanism herein described.

The adjustment of the clearance between the star 286 and the cam 285 is accomplished by loosening the set screw 2I6, which at the same time loosens the eccentric collar 284 imposed between the double bearing support arm and the.

case of the intermittence movement. The adjustment is accomplished by moving the eccentric collar 284 without disturbing the double bearing support-arm. This is a desirable feature since the star shaft tends to seat itself in the top.

segment of the double bearing after operation of the machine for some periodof time. The seating in the top segment is caused by the continual pulling down of the film by the intermittent sprocket. This is a feature which is different from conventional types of projector heads in which the double bearing arm is swung radially and this brings a new surface of the bearing into use and causes interference in the smoothness of the operation of the intermittent sprocket. After properly adjusting the star 286 in relation to the cam 285 through movement of the eccentric collar 284, the set screw 2I8 is tightened and locks the three units in operating relationship to each other.

The star shaft inner bearing 281 extends out through the double bearing support arm and rests against the inside end surfaces of the in-' termittent sprocket 289, thus providing a definite the intermittent sprocket 289. As soon as there is a drag on the sprocket after the removal of one shim, the shim is replaced and the sprocket will be found to have the proper clearance- A cap 228 seals dirt out of the end bearing and. is

Imposed between provided with a ball oil seal 2l2 to permit lubrication of the sprocket and shaft.

The star and cam movement is shown in de tail in Fig. 21 and comprises thestar gear 205,

which is secured to the star shaft 201. As shown, the periphery of the star gear 296 rides on the surface of the cam 205a on the cam 205 and is contacted by a pin 22l which is carried on the cam 205 and causes the star wheel 206 to move through 90 of movement for each complete revolution of the cam 205.

As shown in Fig. 24, a journal 222 is provided for the bearings I95 and I96, and in the embodiment here shown is cast integrally with the back plate.

In Fig. 19 is shown the construction and ar rangement of the spline connection for driving the intermittence movement so that upon disconnection of the intermittence movement from its drive shaft, the shafts are permitted to mate in but one position in 360 of rotation. In this way removal of the intermittencemovement is accomplished without changing its synchronization with the drive shaft.

Hydraulic control of fire shutter The fire shutter and actuating mechanism is identified generally in the several views by the letter F. In the embodiment of the invention here shown, the fire shutter is raised automatically by hydraulic pressures which are exerted -on the hydraulic cylinder 223 (Fig. 16). The

hydraulic cylinder 223 is connected to the hydraulic line 11 which supplies oil under pressure from the pump 16. The control of pressure in the line 11 is accomplished by theadjustable check valve shown in Fig. 38. As there shown, the pressure adjusting knob II is connected with a shaft 224 which exerts a pressure on a springpressed ball checkvalve 225 which controls the flow of oil from the pump Hi through the oil duct 11. As shown in this view, the oil pump 16 is preferably of the gear type consisting of the meshed gears 226 and 221, although any other suitable type of oil pressure pump may be used.

As shown in Fig. 16, the shutter-operating cylinder 223 consists of a shell 228 in which is mounted a spring-pressed piston 229. A rod 230 is connected with the piston 229 and exerts a pressure on the pedal 231 for the fire trap rack. The spring-pressed piston 229 is raised in such a manner that it returns to the position as shown in ,Fig. 16 upon the release of the hydraulic pres sures thereon. The piston 229 is maintained in the position for raisingthe fire shutter by a constant flow of oil under pressure through the duct 77, which oil is constantly returned through a plurality of ports 232 and vent ports 232a provided in the shell 228 of the cylinder. Thus, when the check valve 225 has been properly'set, the flow of the oil from the pump is at such a rate that when the machine is up to operating speed,

sufficient pressures are generated in the cylinder 223 to move the piston 229 and exert a, pressure on the pedal 23l of the fire trap rack. This movement of the pedal 23I causes the fire shutter 233 to be moved to the open position as shown in Fi 23.

The piston 229 moves in the cylinder 223 only to the point where the relief ports 232 and 232a. are uncovered. At this point excess oil escapes through the relief ports. 232 and 232a and the piston is maintained in the position for exerting a pressure on the pedal 23| for as long as the oil pressure is sutficient to supply the required, 75-,

amount of oil to the cylinder. If the oil pressure drops due to a slowing down of the machine, the action of the spring on the piston 229 restricts the piston and the pedal allows the curtain 233 to move to the closed position as shown in Fig. 22. Upon drop of the predetermined pressures on the hydraulic fluid, the piston is returned to the position shown in Fig. 16 and in returning to this position vents the hydraulic fiuid through the ducts 232a as well as through the ducts 232. Thus the provision of the separate ducts 232a on the top of the cylinder and the ducts 232 on the bottom provides for the quick return of the piston and the quick release of the fire screen shutter.

Thus the ports 232 and 232a serve two purposes in the cylinder. First, they act as a, relief outlet for oil in the line when the oil pressure falls oif, thus allowingian immediate closing of the fire shutter by the action of the springs provided. If the springs fail, the shutter is so arranged, as shown in Fig. 22, that the fire shutter will close by gravity alone, in which event the oil in. the cylinder is forced out of the cylinder by the movement of the piston. Second, the ports 232 at the lower portion of the cylinder act as drain holes for all oil that seeps past the piston. Various types of constructions may be employed to pre'-.

to provide a small rim around the circumference of the piston'head and thus to reduce the contact surfaces between which the hydraulic fluid is held. The internal tension of suchfiuid between the head of the piston and the cylinder head otherwise causes the piston and the cylinder head to adhere to each other after the piston returns to its normal position. A button 234 is provided for the manual operation of the fire shutter.

A better understanding of the operation of the fire shutter 233 will be had from a consideration of Fig. 22 and 23. In Fig. 22 the parts are shown with the shutter in the closed position and in Fig. 23 the shutter is shown in the open position. As here shown, the pedal 231 is formed as the end of a rack gear 235 which has gear teeth which mesh with a rotating pinion gear 233. The pinion gear 236 is operatively connected with a shaft 231 to which the fire shutter 233 is attached. Movement of the rack 235 in response to movement of the shaft 230 by the hydraulicallyoperated piston 229 is thus translated into rotary movement of the shaft 231, which causes the shutter to rotate with the shaft 23 and thus to be raised or low ered relative to the aperture 238. A spring 239 is connected with tre rack 235 and tends to hold the rack in such a position that the shutter 233 is normally maintained in its closed position with its edge in contact with the stop 262. Movement of the parts to bring the shutter to the raised position causes the spring 239 to be extended. Thus, when the hydraulic pressure drops, the shutter 233 tends to move to the closed position by the action of the spring 239, the spring connected with the piston 229, and by the weight of the shutter 233. Thus, in the event of an accidental showing down or stoppage of the machine, the drop in the hydraulic pressurein the line 11 permits the shutter 233 to immediately be closed over the port 233 and it thus shuts off light and heat from the projection light (not shown) and prevents burning of the film.

The shutter 233v may be manually operated by the button 234 which isconnected with a rack 249 which also engages the gear 236 to causero- 

